// iostream is too mainstream
#include <cstdio>
// bitch please
#include <iostream>
#include <algorithm>
#include <cstdlib>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <list>
#include <cmath>
#include <iomanip>
#define dibs reserve
#define OVER9000 1234567890123456789LL
#define ALL_THE(CAKE,LIE) for(auto LIE =CAKE.begin(); LIE != CAKE.end(); LIE++)
#define tisic 47
#define soclose 1e-8
#define chocolate win
// so much chocolate
#define patkan 9
#define ff first
#define ss second
#define abs(x) ((x < 0)?-(x):x)
#define uint unsigned int
#define dbl long double
using namespace std;
// mylittledoge
 
int main() {
	cin.sync_with_stdio(0);
	cin.tie(0);
	int T;
	cin >> T;
	for(int t =0; t < T; t++) {
		int N;
		cin >> N;
		int x =0;
		double y =-(1e8);
		for(int i =0; i < N; i++) {
			int a,b,c;
			cin >> a >> b >> c;
			double r =0.5*b/a;
			double z =-a*r*r+b*r+c;
			y =max(y,z);
			if(z >= y-0.1) x =i+1;}
		cout << x << "\n";}
	return 0;}
 
// look at my code
// my code is amazing

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

MwoxCjEgNCAyCjIKMyAxMjYgMTQwMAoyIDE1MiAyMDgKMgozIDEyNyAxNDAwCjIgMTU0IDIwOAo=

3
1
1 4 2
2
3 126 1400
2 152 208
2
3 127 1400
2 154 208